常澤輝,賈檸澤,侯 靜,鄭宏飛,李文龍,劉 洋
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聚光回熱式太陽能土壤滅蟲除菌裝置光熱性能
常澤輝1,2,賈檸澤1,侯 靜3,鄭宏飛4,李文龍1,劉 洋1
(1. 內蒙古工業(yè)大學能源與動力工程學院,呼和浩特 010051; 2. 內蒙古工業(yè)大學風能太陽能利用技術省部教育部重點實驗室,呼和浩特 010051; 3. 內蒙古工業(yè)大學化工學院,呼和浩特 010051; 4. 北京理工大學機械與車輛學院,北京 100081)
該文針對傳統(tǒng)設施農業(yè)土壤滅蟲除菌過程使用化學消毒法所帶來的環(huán)境污染和農作物藥物殘留等問題,提出了新型聚光回熱式太陽能土壤滅蟲除菌裝置,利用太陽能聚光集熱技術加熱空氣進而對農業(yè)種植土壤進行高溫消毒,同時將土壤所含有機物加熱揮發(fā),實現(xiàn)對農業(yè)種植土壤的修復,同時處理后的熱土壤對進料空氣進行預熱,提高了裝置的熱能利用效率。該文介紹了聚光回熱式太陽能土壤滅蟲除菌裝置的工作原理,利用光學仿真軟件對裝置中復合多曲面聚光器的光學效率進行了計算,基于光學計算結果,對聚光回熱式太陽能土壤滅蟲除菌裝置的光熱性能進行了室外試驗,測試了裝置的空氣加熱溫度和集熱效率。結果表明,用于土壤滅蟲除菌的熱空氣在聚光比為3.6,流動速度為1.075 m/s時,裝置的集熱效率最高,加熱后空氣溫度最高達到了88 ℃左右,集熱效率為65%左右,能夠滿足農業(yè)土壤滅蟲除菌所需的溫度需求。
土壤;滅菌;太陽能集光器;聚光;太陽能;光熱轉化效率
設施農業(yè)內作物長期在高溫、潮濕的微環(huán)境下生長,這為土壤中病原菌和害蟲的繁殖、生長提供了適宜的條件,加之設施農業(yè)發(fā)展迅速、多年重茬連作,使得土壤種植環(huán)境不斷惡化,病蟲害逐年累積,導致土傳病蟲害連年爆發(fā),成為了制約設施農業(yè)可持續(xù)發(fā)展的瓶頸[1]。常規(guī)的化學防治手段對環(huán)境和人員毒副作用大,農業(yè)手段可行性不高[2]。隨著溴甲烷的禁用和對無公害綠色蔬菜的需求日益增加,物理土壤消毒技術受到了國內外研究學者的關注[3-13]。Gay等[14-15]設計、建造了由履帶車輛牽引的土壤蒸汽滅蟲裝置,分析了裝置中非常規(guī)蒸汽噴射系統(tǒng)的性能,測試了不同土壤深度溫度隨裝置運行時間變化的趨勢。張燕麗等[16]對覆膜加麥麩太陽能消毒技術對土壤溫度的影響進行了試驗研究,結果表明試驗土壤地下30 cm處溫度可以保持在44.8 ℃,有效降低番茄枯萎病的發(fā)病率。杜蕙等[17]研究了太陽能消毒時覆膜與添加有機物對土壤溫度的影響機理,試驗中,0~20 cm深度內土壤最高溫度可以達到40 ℃,顯著增大了土壤日溫差,使得對病害的控制效果得到了提升。吳雪芬等[18]進行了夏季土壤高溫消毒、太陽能日曬消毒、石灰消毒和生物技術等土壤消毒技術對比試驗,證明無公害土壤消毒技術對土壤病蟲害控制作用明顯。
現(xiàn)有的土壤物理滅殺技術主要是利用高溫工作介質或電流殺死害蟲、致病菌和雜草種子,隨著滅殺效果的提高,滅殺過程所需要消耗的化石能源需求量也很高[19-21]。如果能夠減少化石能源的使用,利用太陽能集熱技術對設施農業(yè)種植土壤進行高溫處理[22-26],同時使得土壤中有機物受熱揮發(fā)排出土壤作進一步處理,有效消滅初侵染源,促進土壤形成“生物真空”,然后接種有益微生物,進而提高設施農業(yè)農產品品質[27]。那么對此技術開展研究的意義就不言而喻了。
鑒于此,本文在前期研究基礎上,結合設施農業(yè)土壤滅蟲除菌的溫度要求,設計了一種聚光回熱式太陽能土壤滅蟲除菌裝置。其具體結構及工作原理如圖1所示。
其工作原理是空氣經引風機抽入到位于槽式復合多曲面太陽能聚光器焦斑位置的雙層玻璃真空管內管狀黑色吸收體中,太陽光經聚光器匯集形成高密度光能,對吸收體內的流動空氣進行加熱,空氣將在吸收體遠離引風機端口處溫度達到最高,然后進入到帶保溫層的熱空氣腔中,加熱第一級帶褶皺的金屬換熱板上的土壤,對土壤中的致病菌、害蟲和雜草種子進行高溫滅殺,隨后空氣經蘑菇型通風道進入到尾氣回流通道,蘑菇型通風道可以將土壤和熱空氣分開流通,避免相互混合接觸,處理后的土壤在重力和自振彈簧振動作用下沿換熱板下滑到第二級帶褶皺的金屬換熱板上,然后繼續(xù)下滑到滑送帶排出裝置,從第二級帶褶皺的金屬換熱板到離開裝置過程中,高溫土壤與經蘑菇型通風道進入的新鮮空氣換熱,實現(xiàn)裝置的熱土壤回熱功能,土壤中的有機揮發(fā)物受熱氣化后從裝置上方排氣管排出并進行后期進一步無害化處理。裝置中利用太陽能消毒抑制農業(yè)土壤病蟲害的基礎是多數(shù)植物病菌和有害生物是中溫的,它們在溫度高于32 ℃以上不能生長,可被高溫直接或間接殺死,而耐高溫和濕熱的有益土壤微生物通常能存活下來[28]。
本裝置具有如下特點:1)裝置利用太陽能聚光加熱的流動空氣對土壤中的致病菌、害蟲和雜草種子等進行物理滅殺及揮發(fā)性有機物的分離,不需要消耗化石能源,不對土壤造成二次污染,提高了農產品品質;2)裝置對換熱后的尾氣進行了再次循環(huán)重復利用,同時處理后的高溫土壤對進料空氣進行了預熱,提高了裝置的熱能利用效率;3)裝置利用土壤的重力和對金屬換熱板端頭安裝彈簧的沖擊產生的自振作用,實現(xiàn)了土壤的半自動滑送和傳輸;4)所采用的槽式復合多曲面太陽能聚光器具有對跟蹤精度要求低、接收體位于聚光器內部、可吸收部分散射光等優(yōu)點。
聚光回熱式太陽能土壤滅蟲除菌裝置光熱性能測試試驗系統(tǒng)實物如圖2所示,測試系統(tǒng)包括槽式復合多曲面聚光系統(tǒng),空氣流速測試系統(tǒng)、空氣溫度檢測系統(tǒng)及太陽能輻射觀測站??諝饬魉贉y試系統(tǒng)的探頭安裝在引風機出風口處,并在管狀黑色吸收體進、出口處沿徑向對稱軸等間距放置3個K型熱電偶,環(huán)境溫度和太陽輻照度由太陽輻射觀測站實時采集。
聚光回熱式太陽能土壤滅蟲除菌裝置通過復合多曲面聚光器將太陽光聚焦到雙層玻璃真空管內,被涂有吸收率高、反射率低的吸收性涂層的直通管式黑色吸收體吸收,進而加熱其內部的空氣。在光熱轉化過程中,由于雙層玻璃真空管內抽成真空,則吸收體與環(huán)境的輻射換熱和對流換熱較少,計算時忽略這部分熱量損失。
測試用直通管式黑色接收體吸收的經槽式聚光器匯聚的太陽輻射能為
式中I是槽式聚光器入光口所接收到的太陽輻照度,W/m2;ape是槽式聚光器的入光口面積,m2;opt是槽式聚光器的光學效率。
直通管式黑色接收體進出口的空氣平均溫度可由下式計算得到
式中T表示3個K型熱電偶所測溫度值,℃。
則直通管式黑色接收體的集熱量為
式中是直通管式黑色接收體內空氣的密度,kg/m3,是管式接收體截面積,m2,V是管式接受體內空氣流速,m/s,C是管式黑色吸收體內流動空氣的定壓比熱容,kJ/(kg·K),in、out是管式黑色吸收體進出口空氣溫度,K。
則裝置的光熱轉換效率為
聚光回熱式太陽能土壤滅蟲除菌裝置中對太陽能進行匯聚的聚光器采用的是槽式復合多曲面聚光器,大大提高了太陽光能流密度[29-30],保證所加熱空氣達到滅蟲除菌需要的溫度范圍(50~90 ℃)。它是由2條拋物線經過旋轉和平移后,再與第3條拋物線經直線連接而成,沿對稱軸平移后形成的。利用光學仿真計算軟件LightTools對槽式復合多曲面聚光器的聚光性能進行計算、分析,對于后續(xù)裝置的跟蹤精度及光熱性能測試具有參考和指導意義。
槽式復合多曲面聚光器的左、右對稱拋物線方程分別為
(6)
底部拋物線方程為
當光線正入射時,聚光器內部光線追跡如圖3所示。直通管式接收體表面能流密度計算結果及分布如圖4所示。
設定直通管式接收體的半徑為22 mm,入光口寬度為500 mm,豎直反射面高度為20 mm,反射面光學反射率為0.8,入射光線設定為柵格匯聚光束,張角為太陽光線張角(0.53°),模擬光束為100×100條,光線輻射強度為700 W/m2。
從圖3可知,正入射到槽式復合多曲面聚光器的光線在理想狀態(tài)下會匯聚到直通管式接收體表面。東西放置的聚光器在運行過程中會受到太陽高度角和太陽方位角的影響,其影響程度決定了裝置對跟蹤系統(tǒng)精度的要求,進而會影響到裝置的滅蟲除菌效果和經濟性。為了便于研究,定義聚光效率為僅考慮入射光的逸出或被遮擋所造成的能量損失,不考慮光的衰減時,直通管式接收體表面接收到的光線輻射強度與入射光線輻射強度之比。光線接受率為接收體表面接收到的光線數(shù)量與通過入光口的入射光線數(shù)量之比。裝置中使用的槽式復合多曲面聚光器的聚光效率、管式接收體表面光線接受率隨太陽高度角跟蹤精度(徑向入射偏角)變化曲線如圖5所示。
圖5曲線變化規(guī)律顯示,槽式聚光器聚光效率、接收體表面光線接受率隨徑向入射偏角的增加而減小。在太陽正入射時,接收體表面光線接受率為99.66%,聚光效率為81.48%,當徑向入射偏角增加為3°時,光線接受率仍為90.57%。隨著入射偏角繼續(xù)增加,光線接受率、聚光效率大體呈直線下降;當徑向入射偏角增加為7°時,接收體表面光線接受率為66.20%。
當太陽方位角跟蹤精度(軸向入射偏角)變化時,聚光器聚光效率和接收體表面光線接受率變化趨勢如圖6所示。
從圖6中可以看出,槽式聚光器的聚光效率、接收體表面光線接受率隨軸向入射偏角的增加而呈直線下降趨勢。當軸向入射偏角增大為2°時,接收體表面光線接受率減小為89.29%,聚光效率減小為73.07%,比正入射時分別減小了11.61%和11.50%。
4.1 試驗測試系統(tǒng)及設備參數(shù)
試驗中,工作介質空氣在直通管式接收體進出口溫度用多路溫度采集儀(TYD-WD,北京天裕德科技有限公司,北京)實時記錄,空氣在直通管式接收體內的流動速度由數(shù)字風速儀(GM8902,深圳市若谷科技有限公司,深圳)實時采集,管式接收體內空氣由引風機(XP-311,惠州市盛鑫科技有限公司,惠州)驅動,用太陽能發(fā)電監(jiān)測站系統(tǒng)(TRM-FD1,錦州陽光氣象科技有限公司,錦州)對試驗地太陽輻照度和環(huán)境溫度進行在線監(jiān)測。測量空氣溫度所用熱電偶為K型熱電偶,測量精度為±1 ℃。
試驗測試前,對數(shù)字風速儀、K型熱電偶、太陽總輻射表、測溫儀等進行測試精度校核。裝置中所使用的槽式復合多曲面聚光器為自行制作,尺寸規(guī)格完全與仿真計算模型一致,反射面貼有反射率為80%的鋁板,可以實現(xiàn)對太陽雙軸跟蹤。雙層真空玻璃集熱管為定做型號,長度為1 000 mm,直通管式接收體內徑為40 mm,壁厚為2 mm。
4.2 測試方法
設施農業(yè)種植用土溫度在冬季為全年最低,如果聚光回熱式太陽能土壤滅蟲除菌裝置在冬季的光熱性能能夠滿足設施農業(yè)的滅殺要求,則其全年的運行性能就能滿足設施農業(yè)滅蟲除菌的溫度要求。試驗中,對不同空氣流速條件下,空氣的溫升特性進行對比試驗研究?;谇懊嫜b置光學仿真計算結果,測試在太陽高度角跟蹤精度為5°情況下,最佳空氣流速工況時裝置的瞬時熱效率變化曲線。試驗測試時間選定在冬季,地點選擇在內蒙古呼和浩特市(北緯40°50′,東經111°42′)。在管式接收體進出口端面等距放置3個K型熱電偶,其平均值為進出口空氣的有效溫度值。采集的試驗數(shù)據(jù)包括太陽總輻射值I,空氣流速V,環(huán)境溫度T,空氣進口溫度in,空氣出口溫度out,太陽直接輻照度E。
4.3 測試結果及分析
在相近太陽輻照度和環(huán)境溫度條件下,改變聚光回熱式太陽能土壤滅蟲除菌裝置中直通管式接收體內空氣流動速度,測試不同空氣流速下,經槽式復合多曲面聚光器加熱后的空氣溫升曲線,如圖7所示。
由圖7可以看出,在相同運行時間內,穩(wěn)態(tài)運行的直通管式接收體進口平均溫度約為?6 ℃時,接收體出口空氣溫度隨空氣流速的減小而增加。在相同流速條件下,空氣溫度變化很小,輸出穩(wěn)定。當空氣流速為1.075 m/s時,接收管出口空氣最高溫度可以達到79 ℃左右,約比空氣流速為4.076 m/s時的溫度高70 ℃。對上述空氣流速條件下的裝置光熱轉換效率進行計算,如表1所示。
表1 不同空氣流速下裝置光熱效率對比
表1計算結果表明,在太陽輻照度相近,直通管式接收體進口溫度相同條件下,裝置光熱轉換效率隨管式接收體內空氣流速增加而減小,在空氣流速為1.075 m/s時,光熱轉換效率可以達到62.18%,比空氣流速為4.076 m/s時增加了84.51%,出口空氣溫度達到了78.45 ℃,滿足了設施農業(yè)土壤滅蟲除菌所需溫度要求。在實際設施農業(yè)土壤滅蟲除菌運行時,需要將入光口面積增加為試驗測試裝置入光口面積的數(shù)倍,以進一步提高裝置的運行效果。
在晴好天氣,槽式復合多曲面聚光器中管式接收體內的空氣流速選為1.075 m/s,對太陽高度角單軸跟蹤,無風條件下,測試裝置的運行環(huán)境溫度、太陽輻照度,變化曲線如圖8所示。測試管式接收體出口空氣溫度隨太陽輻照度和環(huán)境溫度變化曲線如圖8所示,瞬時聚光器光熱轉換效率,出口空氣溫度變化曲線如圖9所示。
從圖9可以得出,直通管式接收體出口空氣溫度、裝置光熱轉換效率隨太陽輻照度的變化而變化。當進口空氣溫度為?1 ℃左右時,直通管式接收體出口空氣溫度最高可以達到88 ℃左右,最低溫度也在50 ℃以上,光熱轉換效率可以達到65%左右。滿足了冬季設施農業(yè)土壤滅蟲除菌的溫度要求,則設施農業(yè)全年的土壤滅蟲除菌溫度需求可以得到保證。
聚光回熱式太陽能滅蟲除菌裝置所產生的熱空氣通過金屬換熱板對設施農業(yè)用土進行升溫滅蟲除菌,在夏秋季節(jié)運行效果會比冬季更好。在此過程中,土壤的濕度、進料速度、堆積厚度以及初始溫度等因素都將影響到裝置的滅殺效果和經濟性,下一步我們將對上述因素的影響機理展開試驗測試和理論分析。
本文針對設施農業(yè)常規(guī)土壤滅蟲除菌過程中使用農藥對土壤和人員的危害及物理滅殺過程需要使用大量化石能源的問題,結合區(qū)域發(fā)展特點,提出了聚光回熱式太陽能土壤滅蟲除菌裝置,盡可能地減少了設施農業(yè)對土壤處理過程中對環(huán)境的二次污染和化石能源消耗量,提高設施農業(yè)農產品品質。同時對裝置的光熱性能進行了仿真計算和試驗測試。
1)裝置中所設計的槽式復合多曲面聚光器,經過光學仿真軟件LightTools的分析和計算,結果表明,在太陽正入射時,接收管表面光線接受率為99.66%,能量轉化效率為81.48%,當徑向入射偏角為3°時,管式接收體表面光線接受率仍為90.57%,接收體表面光線接受率和能量轉化效率隨軸向入射偏角的增加而呈直線下降趨勢,能夠為聚光回熱型太陽能土壤滅蟲除菌裝置提供高密度熱能,跟蹤精度要求低。
2)聚光回熱型太陽能土壤滅蟲除菌裝置利用槽式復合多曲面聚光器對工作介質空氣進行加熱,在進口空氣溫度為?1 ℃時,直通管式接收體出口空氣溫度可以達到88 ℃,達到設施農業(yè)土壤滅菌除蟲的溫度要求。
3)隨著聚光回熱型太陽能土壤滅蟲除菌裝置中工作介質空氣流速的減小,管式接收體出口空氣溫度升高,裝置光熱轉化效率提高,在對太陽高度角單軸跟蹤時,冬季室外試驗中,該裝置的光熱轉化效率可以達到65%左右。
[1] 趙婷婷. 不同土壤消毒方式對大棚西瓜連作障礙抑制效果的研究[D]. 楊凌:西北農林科技大學,2016.
Zhao Tingting. Researching the Effects of Different Soil Disinfection Methods on the Continuous Cropping Obstacle of Watermelon in Plastic Shed [J]. Yangling: Northwest A & F University, 2016. (in Chinese with English abstract)
[2] 楊雅婷,胡檜,趙奇龍,等. 土壤物理消毒裝備研究進展[J]. 農業(yè)工程,2015,5(11):43-48.
Yang Yating, Hu Hui, Zhao Qilong, et al. Research progress of soil physical disinfection equipment[J]. Agriculture Engineering, 2015, 5(11): 43-48. (in Chinese with English abstract)
[3] Berrtuo R, Gay P, Piccarolo P, et al. Grey-box models for steam soil disinfestation simulation[J]. Mathematics and Computers in Simulation, 2004, 65: 191-200.
[4] Antonio Gelsomino, Beatrix Petrovicová, Francesco Zaffina, et al. Chemical and microbial properties in a greenhouse loamy soil after steam disinfestation alone or combined with CaO addition [J]. Soil Biology & Biochemistry, 2010, 42: 1091-1100.
[5] Roux-Michollet D, Czarnes S, Adam B, et al. Effects of steam disinfestation on community structure, abundance and activity of heterotrophic, denitrifying and nitrifying bacteria in an organic farming soil[J].Soil Biology & Biochemistry, 2008, 40: 1836-1845.
[6] 李萍萍. 設施園藝中的土壤生態(tài)問題分析及清潔生產對策[J]. 農業(yè)工程學報,2011,27(12):346-349.
Li Pingping. Soil ecological problem and its resolvent in greenhouse horticulture[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2011, 27(12): 346-349. (in Chinese with English abstract)
[7] 辜松,王忠偉. 日本設施栽培土壤熱水消毒技術的發(fā)展現(xiàn)狀[J]. 農業(yè)機械學報,2006,37(11):168-170.
Gu Song, Wang Zhongwei. Soil disinfection with hot water in Japan[J]. Transactions of the Chinese Society for Agricultural Machinery, 2006, 37(11): 168-170. (in Chinese with English abstract)
[8] 隋俊杰. 土壤電消毒滅蟲機在設施農業(yè)中的應用[J]. 農業(yè)工程,2012,2(S1):35-38.
Sun Junjie. Application of soil electrical disinfection and pest control machine in facility agriculture[J]. Agricultural Engineering, 2012, 2(S1): 35-38. (in Chinese with English abstract)
[9] 劉濱疆. 物理農業(yè)的應用及其產業(yè)化[J].農業(yè)工程,2012,2(6):4-10.
Liu Binjiang. Application and industrialization of physical agriculture[J]. Agricultural Engineering, 2012, 2(6): 4-10. (in Chinese with English abstract)
[10] 許光輝,趙奇龍,高宇. 火焰高溫消毒技術防治農田土壤病蟲害研究與試驗[J]. 農業(yè)工程,2014,4(10):52-54.
Xu Guanghui, Zhao Qilong, Gao Yu. Research and experiment on preventing soil pests by high temperature flaming sterilization technology[J]. Agricultural Engineering, 2014, 4(10): 52-54. (in Chinese with English abstract)
[11] 王明友,肖宏儒,宋衛(wèi)東,等. 微波處理對溫室連作土壤中根結線蟲的影響[J]. 中國農機化學報,2013,34(4):95-99.
Wang Mingyou, Xiao Hongru, Song Weidong, et al. Influence of microwave treatment on the root-knot nematodes of continuous cropping soil in the greenhouse[J]. Journal of Chinese Agricultural Mechanization, 2013, 34(4): 95-99. (in Chinese with English abstract)
[12] Pinel M P C, Bond W, White J G. Control of soil-borne pathogens and weeds in leaf salad monoculture by use of a self- propelled soil-steaming machine[J]. Acta Horticulturae, 2000(532): 125-130.
[13] Lu P, Ricauda Aimonino D, Gilardi G, et al. Efficacy of different steam distribution systems against five soil-borne pathogens under controlled laboratory conditions[J]. Phytoparasitica, 2010(38): 175-189.
[14] Gay P, Piccarolo P, Ricauda Aimonino D, et al. A high efficiency steam soil disinfestation system, part I: Physical background and steam supply optimisation[J]. Biosystems Engineering, 2010, 107: 74-85.
[15] Gay P, Piccarolo P, Ricauda Aimonino D, et al. A high efficacy steam soil disinfestation system, part II: Design and testing[J]. Biosystems Engineering, 2010, 107: 194-201.
[16] 張燕麗,李建設,史娟. 覆膜加麥麩太陽能消毒對土壤溫度及番茄生長狀況的影響[J]. 北方園藝,2014(2):49-52.
Zhang Yanli, Li Jianshe, Shi Juan. Effect of solarization with plastic-film mulching and wheat bran on soil temperature and growth of tomato[J]. Northern Horticulture, 2014(2): 49-52. (in Chinese with English abstract)
[17] 杜蕙,漆永紅,呂和平. 太陽能消毒時不同處理方式對土壤溫度的影響[J]. 北方園藝,2012(8):154-157.
Du Hui, Qi Yonghong, Lü Heping. Effect of different treatment on soil temperature under solarization[J]. Northern Horticulture, 2012(8): 154-157. (in Chinese with English abstract)
[18] 吳雪芬,周英,陳軍,等. 土壤消毒技術在安全無公害蔬菜生產上的應用[J]. 安徽農業(yè)科學,2015,43(11):85-87.
Wu Xuefen, Zhou Ying, Chen Jun, et al. Application of soil sterilization technology in safe and pollution-free vegetable production[J]. Journal of Anhui Agri. Sci., 2015, 43(11): 85-87. (in Chinese with English abstract)
[19] 施印炎,李成光,汪小旵,等. 可移動式土壤蒸汽消毒機的設計[J]. 中國農機化學報,2017,38(1):56-59.
Shi Yinyan, Li Chenggang, Wang Xiaochan, et al. Design of removable soil steam sterilization machine[J]. Journal of Chinese Agriculture Mechanization, 2017, 38(1): 56-59. (in Chinese with English abstract)
[20] 卓杰強,陳立振,周增產,等. 無土栽培基質蒸汽消毒機研究與應用[J]. 農機化研究,2012,34(9):95-98.
Zhuo Jieqiang, Chen Lizhen, Zhou Zengchan, et al. Research and application of soilless cultivation matrix steam disinfection machine[J]. Journal of Agricultural Mechanization Research, 2012,34(9): 95-98. (in Chinese with English abstract)
[21] 包應時,吳曉蓮. 設施園藝基質消毒設備的研制[J]. 農機化研究,2011,33(4):107-141.
Bao Yingshi, Wu Xiaolian. Horticulture development matrix disinfection equipment[J]. Journal of Agricultural Mechanization Research, 2011, 33(4): 107-141. (in Chinese with English abstract)
[22] Kita N. Physical soil sterilization for soil-borne disease control[J]. Proceedings of Vegetable and Tea Science, 2006(3): 7-15.
[23] 張麗英,李賀年,翟珊珊,等. 太陽能土壤消毒在草莓保護地栽培中的應用效果[J]. 北方園藝,2010(14):67-68.
Zhang Liying, Li Henian, Zhai Shanshan, et al. Effects of solar soil disinfection technology on strawberry protected planting[J]. Northern Horticulture, 2010(14): 67-68. (in Chinese with English abstract)
[24] 漆永紅,杜蕙,曹素芳,等. 日光高溫消毒方式對土壤根結線蟲的防治效果[J]. 中國農學通報,2015,31(35):122-127.
Qi Yonghong, Du Hui, Cao Sufang, et al. Control effect of solarization mode on soil root-knot nematode [J]. Chinese Agricultural Science Bulletin, 2015, 31(35): 122-127. (in Chinese with English abstract)
[25] Pinkerton J N, Ivors K L, Miller M L, et al. Effect of soil solarization and cover crops on populations of selected soilbrone plant pathogens in western oregon[J]. Plant Disease, 2000, 84(9): 952-960.
[26] Nico A I, Jimenez-Diaz R M, Castillo P. Solarization of soil in piles for the control of Meloidog yne incognita in olive nurseries in southern Spain[J]. Plant Pathology, 2003, 52(6): 770-778.
[27] 李英梅,曹紅梅,徐福利,等. 土壤消毒措施對土壤物理特性及黃瓜生長發(fā)育的影響[J]. 中國生態(tài)農業(yè)學報,2010,18(11):1189-1193.
Li Yingmei, Cao Hongmei, Xu Fuli, et al. Effects of different forms of soil disinfection on soil physical properties and cucumber growth[J]. Chinese Journal of Eco-Agriculture, 2010, 18(11): 1189-1193. (in Chinese with English abstract)
[28] Katan J. Physical and cultural methods for the management of soil-borne pathogens[J]. Crop Protection, 2000, 19(8): 725-731.
[29] 王金平,王軍,張耀明,等. 槽式太陽能聚光集熱器傳熱特性分析[J]. 農業(yè)工程學報,2015,31(7):185-191.
Wang Jinping, Wang Jun, Zhang Yaoming, et al. Analysis of heat transfer characteristics for parabolic trough solar collector[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2015, 31(7): 185-191. (in Chinese with English abstract)
[30] 楊選民,王亞軍,邱凌,等. 槽式拋物面太陽能聚光集熱器供熱厭氧反應器研究[J]. 農業(yè)機械學報,2016,47(7):202-207.
Yang Xuanmin, Wang Yajun, Qiu Ling, et al. Design and implementation of parabolic trough concentrator heating anaerobic reacto[J]. Transactions of the Chinese Society for Agricultural Machinery, 2016, 47(7): 202-207. (in Chinese with English abstract)
Performance on concentrating regeneration type solar soildeinsectization and sterilization device
Chang Zehui1,2, Jia Ningze1, Hou Jing3, Zheng Hongfei4, Li Wenlong1, Liu Yang1
(1.010051,;2.010051,; 3.010051; 4.100081,)
In the last several decades, the problem of food shortage has been one of the main challenges in the world. It is necessary to enhance the use of protected agriculture in order to promote better microclimate conditions allowing high productivity, stable quality, earliest harvest dates and thus better economic output and good environment quality and food security. However, there are pests and pathogenic bacteria in the soil of agriculture production systems due to an ideal temperature, no wind and high humidity conditions in soil. Then soil disinfection treatments are used in agriculture before planting high-value cash crops, to reduce soil-borne crops pests including bacterial, fungal and nematode pathogens, weeds and insects. Methyl bromide fumigation is the widely used as a disinfection method due to its low cost and high effectiveness. But gaseous methyl bromide may destroy stratospheric ozone. Hence, forthcoming agro-ecological techniques should both reduce pollution hazards and be compatible with sustainable development guidelines. Many other chemical fumigants have become strongly restricted and more ecological treatments are now been sought. Alternative sustainable techniques such as soil electrical disinfection, steam soil disinfection and flame soil disinfection are utilized. However, many of these methods have the major drawbacks of their effect strongly depends on fossil energy. Moreover, the employment on a large scale of these methods could lead to a strong increase in environmental pollution. For this reason, in this paper, we presented a novel concentrating regeneration type solar soil extermination and sterilization device, which used high temperature air to kill soil-borne crop pests, reducing the employment of chemical fumigants and improving the quality of agriculture products. The device consisted of trough compound parabolic concentrating system, soil feed system, soil and air regeneration system and forced draft system, et al. The operational principle of concentrating light and regeneration type solar soil extermination and sterilization device was introduced. A 3D model of the concentrator supported with optical analysis software was used to analyze the tracking accuracy. The distribution of the concentrated light of the absorber could be visualized. Based on the simulation results, an experimental set-up, which can be used to verify the heat collection efficiency and the heating temperature, was designed and constructed. The results indicated that the overall ray’s receiving rate of the trough compound parabolic concentrating collector of 99.66%-62.20% were obtained with radial incidence angles of 0°-7°. The outlet air temperature of the device increased with the decreasing the air flow rate. The maximum outlet air temperature of the device at the air flow rate of 1.075m/s was higher than that of the device at the air flow rate of 4.076 m/s by 70 ℃. Under good sunshine in winter, the outlet air maximum temperature of the device with the tracking accuracy of 5°and the concentrating rate of 3.6 can reach to 88 ℃, and the heat efficiency can reach about 65%, thus, it is able to provide enough heat to soil disinfection in the protected agriculture, which is an idea solar soil extermination and sterilization method for protected agriculture.
soil; sterilization; solar concentrator; concentrating; solar energy; Light-thermal conversion efficiency
10.11975/j.issn.1002-6819.2017.09.027
TK519
A
1002-6819(2017)-09-0211-07
2016-12-21
2017-04-12
國家自然科學基金項目(51666013);內蒙古自然科學基金項目(2013MS0704,2015MS0545);內蒙古工業(yè)大學風能太陽能利用技術省部共建教育部重點實驗室開放基金(201511);內蒙古工業(yè)大學科學研究重點項目(ZD201507)
常澤輝,男(漢族),內蒙古人,副教授,博士,主要從事太陽能海水淡化、光熱利用研究。呼和浩特內蒙古工業(yè)大學能源與動力工程學院,010051。Email:changzehui@163.com
常澤輝,賈檸澤,侯 靜,鄭宏飛,李文龍,劉 洋. 聚光回熱式太陽能土壤滅蟲除菌裝置光熱性能[J]. 農業(yè)工程學報,2017,33(9):211-217. doi:10.11975/j.issn.1002-6819.2017.09.027 http://www.tcsae.org
Chang Zehui, Jia Ningze, Hou Jing, Zheng Hongfei, Li Wenlong, Liu Yang. Performance on concentrating regeneration type solar soildeinsectization and sterilization device[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2017, 33(9): 211-217. (in Chinese with English abstract) doi:10.11975/j.issn.1002-6819.2017.09.027 http://www.tcsae.org